The invention relates to a connecting coupling in several parts, comprising at least one nozzle and a coupling piece for joining hose lines together, in particular for the pressure-tight connection of the hose line of a dishwashing sprayer to a single-lever pillar mixer for a sink.
For reciprocally connecting hose lines or for rapidly and easily connecting a hose line to a faucet, couplings with a bayonet connector are already known, which comprise a hose nozzle, to be inserted into the hose line, and a coupling piece, which fits over the hose nozzle. The hose nozzle has a head part, which is enlarged in diameter, into which a seal is inserted in the face end, while the overlapping coupling piece contacts the rear face end of the head part. On its connecting face end, the coupling piece has two receiving grooves and two hook-shaped coupling pegs, which each engage in provided grooves of the coupling piece disposed on the hose line to be connected or on the faucet. The pressure-tight connection is produced by reciprocally aligned rotation of the coupling pieces; the hose nozzles inserted into the hose lines are pressed against each other and produce a pressure-tight connection by means of the seal disposed on face end. These bayonet couplings are embodied as very compact and are predominantly made of a metal, since the relatively high tensile and compression forces are received and transmitted by only the two coupling pegs. Bayonet couplings are relatively expensive in their manufacture and due to their compact embodiment, are not suited for all uses, such as when the axial spacing between the lines to be connected or joined is tight.
Another known connecting coupling manufactured of plastic material is likewise made in two parts. The hose socket to be inserted into the hose line to be connected has a cylindrical section with an O-ring inserted into a groove, at which a sealing stop cone connects to another cylindrical section that follows. This structural embodiment creates a shoulder, between the sealing cone and the cylindrical section that follows, over which are fitted retaining claws of the coupling piece, which are disposed on its face end. The coupling piece has a bore for receiving the cylindrical connecting section and the sealing cone of the hose nozzle and is provided with the above mentioned retaining claws on its coupling face end. Through the wedge action of a fitted, axially slidable actuating ring, which is prestressed by means of a spring, the elastically embodied, slightly resilient retaining claws are released in an open position, for plugging the hose nozzle into the coupling piece, and are locked in a closed position, in which they secure the pressure-tight connection with the help of the spring tension of the spring disposed in the actuating ring. This connecting coupling has a number of practical advantages. However, it is too complicated in its overall structural design, and as a result its production costs are too high. In an improvement of this above-described connecting coupling, the hose nozzle has only one cylindrical connecting section to be inserted into the coupling piece, and this section is provided with an O-ring disposed in a groove and a retaining groove disposed behind it. The coupling piece in turn has an actuating ring, which is prestressed by means of a spring and which can be disposed so that it can slide axially or rotate. To maintain a pressure-tight connection when the hose nozzle is plugged in, blocking wedges disposed in openings are provided, which engage the retaining groove of the hose nozzle and can be brought into an open or closed position by sliding or rotating the actuating ring. Despite the reduction in structural dimensions achieved, the structural design of this connecting coupling is still too complicated and its manufacture is too expensive.